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gorann

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Everything posted by gorann

  1. Andromeda Asi 071 First Light

    Great image Richard! I saw that ad and was very tempted, but instead I tried to talk him in to keep the camera as he was moving to Australia and was going to use his DSLR there. If there is one place you need a cooled camera, it is Australia (I once tried DSLR AP there). You surely got a lot of bang for the buck, and clearly you already found out how to swing it!
  2. The Bubble. An ongoing project.

    Great start. I also thought it looked a bit soft. Could it be seeing? With some almost not noticeable mist in the air I get soft images like that and then suddenly one night everything is very sharp. Maybe you should go for Lum and Ha on the clearest nights?
  3. I agree with Olly, but it is probably because I am in a rural area where nature produces enough exciting sounds at night. My favorites are the many varied sounds of the tawny owls. Last time I was in my obsy I had one of them flying a meter over my head - fortunately I did not drop any expensive optics.
  4. Very good to know about the QHY5L-II messing things up. Not something one immediately would suspect. That is my guide camera too and it tells me that I need it on a separate computer when I start using a PC for the imaging.
  5. Sorry for the multiple posts. I pressed submit once, and then twice and still nothing seemed to happen. Just goes to show how low tech I am.....
  6. Yes, with AP at least one USB cable is needed for the guiding unless I sell my car and buy a super mount that can do its job without guiding.
  7. Yes, with AP at least one USB cable is needed for the guiding unless I sell my car and buy a super mount that can do its job without guiding.
  8. I don't think you can be more low-tech than me. I only use one USB cable and that is for PHD2. I find the target using the SW hand control on the EQ8, frame it using some high-ISO exposures combined with live view on the screen of my DSLRs, focus manually on a star using live view with 10x magnification (works like a charm). In addition, to avoid power spikes I run everything (mount and heaters) from an ordinary car battery continuously charged by one of these modern electronic chargers (same battery for 2.5 years - no problem). My plan is to start using my chilled CCD and then at least I need two USB cables to work, I know that will cause problems......
  9. Thanks Yves, I also heard from Wim that the buffer helps getting rid of amp glow since the amp does not have to work as hard, and that this is the reason for amp glow in ASI and no amp glow in QHY. I now had a look at the QHY series. For those of us that you got thinking about an OSC but only have optics that can fill an APS-C sensor, it seems to me that the QHY168C would be as fantastic as your QHY367. Same read-out noise specs for both chips, and about the same pixel size, but the QHY168C comes in at a third of the price. Of course, many may want to wait for a QHY168M.....
  10. Regarding the number of subs I notice that Yves only used 18x15min (Gain 2800, offset 76) for the image that started this thread, so that would not be so hard on the computer (but maybe a dark site is needed for that).
  11. Does anyone know how the chilled ASI071 (with a Sony APS-C chip) compares to these full format QHY cameras, particularly with regard to noise, amp glow etc. Many of us do not have the optics needed for a full frame OSC.
  12. Very interesting! How does D810A perform compared to the QHY367C - big difference in noise? What is "the 128C"?
  13. I would love a camera like that but most of my imaging equipment would probably not be up to the task of illuminating a chip that size. Would the APS-C sized ASI071 be up to the task? Sony chip and about the same pixel size.
  14. Amazing shot and suspect Olly knows from where..........
  15. Step down filter rings (or homemade cardboard rings) placed in front of the lens do change the aperture and when used in this way they are referred to as aperture masks. They may not be in the perfect place but are often considered adequate and widely used in astrophotography. The best telephoto lenses (unlikely to include zoom lenses as David points out) can produce excellent results wide open (like the Samyang 135 f/2), or may be improved by bringing down the aperture 0.5 to 1 step (see http://www.astropix.com/html/i_astrop/lenses.html). Aperture masks do not necessarily cause vignetting, and may even reduce vignetting, see entry #9 in this thread: https://www.cloudynights.com/topic/518065-step-down-rings/
  16. If you need to step down a camera lens for astrophotography and want to avoid the iris-spikes, you should not use the internal iris but cheap circular rings that you put into the filter thread, like these: https://www.amazon.co.uk/Belmalia-Step-Down-Rings-Filter-Adapters/dp/B00WQ0C7SU/ref=pd_sim_421_2?_encoding=UTF8&psc=1&refRID=Q3WW0YZVRAH8E0K09EGJ However, the best telephoto lenses do not need to be stepped down, a prime example being the Samyang 135mm f/2 ( a 72.5 mm aperture f/2 apo lens that has virtually a flat field without coma for at least my APS-C), which is now so popular in astrophotography (I love mine). My expectation is that no stepping down is needed for the fixed focal length professional Canon and Nikon apochromatic lenses - but as I say I have still to find out about mine, although there are some great images out there on the net, like those by Martin Fransson.
  17. At least a used Canon 300 f/4 in good condition is cheaper than any comparable Apo telescope with a 75 mm aperture. As I said I have not had a chance to try mine yet, but professional lenses like this, we are talking about an apo with ED elements and totally around 7 or 8 lenses to also correct for things like coma and curvature, are likely to be very well corrected. They are meant to be corrected for full size DSLR, but maybe that is to stretch it when it comes to astrophoto, or maybe not. I think you will find many examples on the net of high class astrophotos by these lenses. The Canon 300 f/4 without image stabilization is around 5000 pounds on e-bay but a new one (with image stabilization) is three times the price so they do charge for the nice optics. Edit: Another thing to consider is the quality control. Cheap ED and APO scopes are made in China and then you often have to be lucky to get a good one, while I expect that the quality control of professional Canon and Nikon lenses (made in Japan) is very rigorous.
  18. Andromeda Galaxy with IFN

    Oh yes, very nice and very different! For some reason I think I would probably have turned it 180°
  19. Olly, does that OSC have a name?
  20. Jesper, you of course also have another option: to buy a telephoto lens. I just bought a Canon EF 300mm F/4 L USM in mint condition for about 500 pounds on ebay. This in an apo lens with and aperture of 75 mm and it is supposed to have a flat field that covers a full format DSLR chip. I just got it and weather has not permitted me to test i yet. I expect Nikon has a comparable lens for a similar price on e-bay. I was told to stay away from the latest versions with image stabilization since that introduces more lenses that are movable and they are just trouble and of no use for astrophotography. They are also more expensive. I see that you have a DSLR now, but if you are going for a chilled CCD/CMOS in the future there are adapters. Edit: Martin Fransson has a Canon EF 300mm F/4 L USM and has taken some splendid images with it Cheers
  21. About EQ3-2 weight limit

    Well, there are two major things wrong with the AR102 (don't think there is an AR100). First, it is an achromat so you will have a poor colour correction that is usually found unacceptable by imagers (but could be ok for visual use). Second, it is too heavy for your mount. It weighs 4.7 kg and that is without a camera. It is also slightly less light sensitive (f/6.5 compared to f/6) and finally it is longer so even more difficult to handle by the mount.
  22. About EQ3-2 weight limit

    This is a great little apo scope for astrophotography (I have one and like it a lot): https://optcorp.com/collections/apochromatic-telescopes/products/explore-scientific-80mm-f-6-essential-series-triplet-refractor-ed0806-01 It weighs 3.4 kg (including the star diagonal which you will not use for AP - I think it is 2.8 kg without) and with a camera you will probably still be below 4 kg, so your mount may be able to handle it.
  23. HaRGB Soul with Star 71 and 100D

    If you add Ha as Lum without adding Ha to the red channel, it will light up areas where there is not much red, which will then turn pinkish. So if you use Ha as Lum then you should first also blend some Ha into the red channel so it can light up its own signal. Another problem with using Ha as Lum is that it will mess up the stars. Stars are quite small in Ha images and I can see in your image that you lost star colour since your Ha-Lum has only lit up the centre of the stars (zooming in I can see some faint colour around the stars). You may have to use layer masks to only add the Ha-Lum to central details in the nebula.
  24. Paramount MYT question.

    Why the h--l did someone come up with the idea of reversing the order of the leads? Just to make our lives easier? What's wrong with standards and why cannot a phone cable just be a phone cable? When it happened to me I have a vague memory of finally solving it by reading the manual, which I usually do not do, but by then several hours of great dark sky had been wasted....
  25. HaRGB Soul with Star 71 and 100D

    Aha, you used the Ha for Lum. According to some (like Olly @ollypenrice) that is a no no, but I have done it myself a few times. I guess it may be rather ok for an object like this where most of the signal is Ha anyhow. Did you add some Ha to the red channel also. If not it could be worth a try.
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